Range finder, height finder, and the like



April 23, 1929.

A. BARR ET AL 1,710,641

RANGE FINDER, HEIGHT FINDER AND THE LIKE Filed July 14, 1927 2 Sheets-Sheet FIGJ.

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April 23, 1929- A. BA'RR ET 'AL 1,710,641

RANGE FINDER, HEIGHT FINDER, AND THE LIKE -,.--..--.,.lll,,v l ,L l 1,

45mm, m arm/0 20mm Patented Apr. 23, 1929.

UNITED STATES PATENT OFFICE. 1

ARCHIE-ALI) BARR, WILLIAM STROUD, AND CHARLES DALRYMPLE HAOGILL, OF GLASGOW, SCOTLAND, ASSIGNORS T BARR AND STROUD LIMITED, 0]! GLASGOW,

SCOTLAND RANGE FINDER, HEIGHT FINDER, AND THE LIKE.

Application filed July 14, 1927, Serial No. 205,716, and in Great Britain July 16, 1826.

This invention refers to rangefinders, heightlinders and like optical instruments, hereinafter and in the claims referred to generally as rangefinders, of the type which are movable angular-1y so as to enable observations to be made, for example, upon aircraft at any angle of sight, and which have what will be termed a working head movable with the rangefinder, the working head being rotatable for actuating means in the optical system of the rangefinder for ef fccting measurement of angle.

The object of this invention is to provide mechanism for rotating the working head of a rangefinder of this type, comprising a rotatable operating head, relatively to which the rangefinder is movable angularly, and differential gear to which motion due to angular movement of the rangefinder relatively to the operating head is im arted without causing relative rotation of t e 0P crating and working heads.

The means in the optical system of rangefinders to which this invention refers for cf- 5 footing measurement of angle, may consist of a prism or prisms which by operation of the working head are movable longitudinally, rotationally or otherwise, say, angularly, and the invention is for rangefinders oi the type for which a mounting is provided, the rangefindcr, say of the self contained base type, being arranged with its base horizontaland movable angularly on the mounting about a horizontal axis for elevation and movable with the mounting about a vertical axis for azimuthal training. \Vith a rangefinder so mounted in accordance with this invention the oper ating head is placed upon the mounting so as to be movable only in azimuth therewith, and, relatively to the operating head, the rangefinder and with it the working head, are rotatable for elevation about the horizontal axis, and the mechanism provided operates so that movements of the rangefin der which are imparted for elevation do not cause relative rotation of the operating and working heads, and thus do not atfect the motion in process of transmission from the operating head to the working head.

Some examples of mechanism according to this invention applied to a rangefinder of the self contained base type will now be described with reference to the accompanying drawings, in which Figure 1 is a sectional elevation and Figure 2 is a sectional View of a detail one example.

Figures 3 and 4 are sectional elevations showing modifications.

The drawings show a part say, the middle portion, of a rangefinder A, a mounting B for the rangefinder, the rangefinder being movable angularly on the mounting about a horizontal axis, which is the longitudinal axis of the tubular casing of the ran efinder A, a handle 2 for moving the rangefi nder A angularly for elevation about the horizontal axis, an element C constituting the working head on the rangefinder, head I) on the mounting B.

Figures 1 and 2 show a circular toothed rack 3 concentric with the longitudinal axis of the rangefinder A and fixed to mounting B, a shaft C constituting the workin head movable with the rangefinder, a spindiia 4 rotatable with shaft C, a gear wheel 5 rotatable on shaft C and in mesh with rack 3, a gear wheel 6 rotatable with 5, a gear wheel 7 in mesh with G, rotatable on spindle 4, a gear wheel 8 rotatable on shaft C, and in mesh with wheel 7, a gear wheel 9 rotatable with 8, a ring E rotatable about rangefinder A, a toothed rack 10 on ring E in mesh with wheel 9, a gear Wheel 12 rotatable with operating head I), a toothed rack 11 on ring E in mesh with wheel 12. The gear ratio between 3 and 5 is the same as that between 10 and 9. In this example, Figures 1 and 2, the elements 6, 7 and 8 constitute a differential gear, the princi ial axis of which is the axis of shaft G. The optical system of the rangefindcr mayhave means for effecting measurement of angle similar to that shown in F igures 3 and 4, consisting of a retracting prism F movable longitudinally by mechanism comprising a gear wheel 13 rotatable with shaft C, a gear wheel 14 in mesh with 13, a screw 15 rotatable with 14, and a carrier 16 for prism F movable longitudinally by screw 15.

The description Of FigHIBS 1 and 2 applies also to Figure 3.

In operation of the mechanisms, Figures 1 and 2 and Figure 3, with D held against rotation, angular movement of rangefinder A by handle 2 causes 5 to be rotated by 3, and

showing and an operating 9 to be rotated by 10, whereby 6 and 8 are rotated in opposite directions, and 7 is rotated on spindle l without causing spindle C to be rotated.

Figure 4 shows a segmental rack 17 fixed to and concentric with rangefinder A, a spindle 18 fixed to mounting B, a shaft 19 on mounting B rotatable with operating head D, a spindle 2O rotatable with shaft 19, a gear 21 in mesh with 17 and a gear 22 rotatable with 21, both on spindle 18, a gear 23 rotatable on shaft 19 and in mesh with gear 22, a gear 24: rotatable with 223, a gear 25 rotatable on spindle 20 and in. mesh with 2st, a gear 26 rotatable on shaft 19 and in mesh with 25, a. gear 27 rotatable with 26. Ring H rotatable about rangelinder A, a

rack 28 on ring H in mesh with 27, a gear 29 rotatable with shaft (l, and a rack 30 on ring H in mesh with 29.

In this example, Figure 4:, the elements 24, 25 and 26 constitute a di'lferential gear, the principal axis of which is the axis of shaft 19; and the gearing between 17 and 28 is such that with D held against rotation, motion imparted by 17 is equal to motion transmitted to 28. has with operating head 1) held so as not to rotate, angular movement of rangefinder A about its horizontal axis by handle 2 causes 17 to rotate 211., and thereby causes 22, 23, 24C, 25 (on spindle 20 which is held stationary), 26 and 27 to rotate, 27 operating to so rotate ring H, that gear 29, in mesh with rack 30, moves angularly with the rangefinder, gear 29 and its shaft C which constitutes the working head are not rotated.

1. A rangefinder, a mounting for the rangefinder, the rangefinder being movable angularly for elevation relatively to the mounting, a rotatable working head movable with the rangelinder and thus angularly relatively to the mounting, a rotatable operating head on the mounting relatively to which the rangetinder and working head are movable angularly, mechanism between the operating head and the working head for imparting rotational motion from the operating head to the working head, said mechanism comprising differential gear to elements of which motion due to angular movements of the rangelinder is imparted with out causing relative rotation of th operating and working heads.

2. A rangetinder, a mounting for the rangefinder, the rangelinder being movable angularly for elevation relatively to the mounting, a IOtttttlblfi working head movable with the rangetinder and thus angular-1y relatively to the mounting, a rotatable oper ating head on the mounting relatively to which the rangelinder and working head are movable angularly, mechanism between the operating head and the working head for imparting rotational motion from the operating head to the working head, said mechanism com n'ising diiferential gear to elements of which motion due to angular movements of the rangelinder is imparted without causing relative rotation of the op erating and working heads, the principal axis of said diii'erential gear being not movable angularly with the rangefinder.

8. A rangefinder, a mounting for the ran gelinder, the rangelinder being movable about its longitiuilinal axis on the mounting for elevation and movable with the mounting for azin'iuthal training, a handle for moving the rangelinder for elevation, a working head element on the rangelinder, an operating head on the mounting, a first segmental ack concentric with and movable with the rangcfinder, a first spindle fixed to the mounting, a shaft on the mounting rotatable with the operating head, a second spindle rotatable with the shaft, a first gear in mesh with the first ack and a Second gear rotatable with the first gear, both 011 the first spindle, a third gear rotatable on the shaft and in mesh with the second gear, a fourth gear rotatable with the third gear, a fifth gear rotatable on the second spindle and in mesh with the fourth gear, a sixth gear rotatable on the shaft and in mesh with the fifth gear, a seventh gear rotatable with the sixth gear, a ring rotatable about the rangelinder, a second rack on the ring in mesh with the seventh gear, an eighth gear rotatable with the working head element, and a third rack on the ring in mesh with the eighth gear, for the purposes set forth.

ARCHIBALD BAR-R. 

